c# - how to create a c++\cli wrapper for unmanaged c dll -

i'm confusing myself haven't done before , bit of direction helpful.
trying call c code c# application. have tried using pinvoke finding bit tricky. thought try doing c++\cli wrapper.

there complicated structs have double arrays of variable length hard handle pinvoke.
i've read bit on how done can't figure out. of i've found relates wrapping c++ instead of c. c code exporting functions works java application , jna service. have c code, headers, library , dll rather not make changes existing not upset other consuming applications. c# application calling 64 bit, examples creating win32 libraries, matter?

update: adding code below:
note: 1 function of several , simplest 1 similar.

c header: typedef struct mystruct_t {     double prefix[8];     int length;     double array[1]; } mystruct;  c: extern "c" __declspec( dllexport ) mystruct *dosomething(const mystruct *input, double a) {     mystruct *output;     //dosomething     return output; } 

there's little difference between wrapping c , c++. need make c++/cli class library. write functions in managed c++ ref class wrap native code.

for instance, suppose dll exports function:

int sqr(int x) 

then in class library include header file:

#include <mynativelibrary.h> 

you need supply import library linker.

then can expose function. simplest way wrap functions static methods of ref class. instance:

public ref class class1 { public:     static int sqr(int x)     {         return ::sqr(x);     } }; 

you can consume assembly in c# code other assembly.